Created attachment 122815[details]
The parameter color is changed to orange, but both the preview window and the editor shows it as blue, which is the color of Identifiers
In any color scheme, changing the color of a function parameter/argument in Netbeans 7.2 is negated. It seems to be using the color value of the Identifier.
See screenshot.

Coloring troubles should be fixed due to issue #218656. BTW, in the new JS editor is not supported coloring of parameters for now (as it never probably worked before), but feel free to raise a new enhancement for improving coloring categories (and adding parameters there).
*** This bug has been marked as a duplicate of bug 218656 ***